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Frequency-Dependent Signal-Correlation in Surround- And Stereo-Microphone Systems and the Blumlein-Pfanzagl-Triple (BPT)

With the aim to recreate the original concert-hall sound-field as faithfully as possible in the control- or living-room recordings were made simultaneously with an artificial head and several surround-microphone techniques (among them the new BPT method). The surround recordings were re-recorded using the same dummy-head as in the concert-hall. The results of subjective listening tests (loudspeaker as well as binaural) were assessed using ANOVA and correlation analysis.
Acoustical analysis of the dummy-head recordings was performed by measuring the ‘Frequency-dependent Inter Aural Cross-correlation Coefficient’ (FIACC): the ‘low-correlation’ AB-PC microphone system was capable of reproducing the original sound-field better than any of the other systems under test (DECCA, KFM, OCT).
A microphone-systems ‘Critical Frequency’, below which correlation raises towards 1, is defined.